Position Sensitive Detector (PSD) chips are specialized semiconductor devices used for the detection of the position and/or intensity of a light source. PSDs typically consist of a photodiode with four segmented electrodes that detect the position of the incident light. As the light strikes the photodiode, it generates an electrical charge that is read by the four electrodes. By analyzing the electrical signals from the electrodes, the position and/or intensity of the light source can be determined. PSD chips are commonly used in a variety of applications, including laser beam alignment, barcode scanning, and machine vision systems.